Photocatalytic degradation of cationic and anionic dyes in water using hydrogen-terminated silicon nanowires as catalyst

Brahiti, N.; Hadjersi, Toufik; Amirouche, S.; Menari, H.; Elkechai, Omar

doi:10.1016/j.ijhydene.2018.02.141

Cited by 21 publications

(8 citation statements)

References 26 publications

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“…Yet, the tip of the nanowires flock amongst themselves to from small wells within the ‘nano-grove’ architecture. Wells dole out evenly over the entire surface area most likely due to van der Waals interactions [ 34 , 35 ] between the adjacent SiNWs. SEM images show AgNPs homogenously decorated on the SiNWs’ surface ( Fig.…”

Section: Resultsmentioning

confidence: 99%

Ultra-sensitive and fast optical detection of the spike protein of the SARS-CoV-2 using AgNPs/SiNWs nanohybrid based sensors

Daoudi

Ramachandran

Alawadhi

et al. 2021

Surfaces and Interfaces

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Severe acute respiratory syndrome SARS-CoV-2 virus led to notable challenges amongst researchers in view of development of new and fast detecting techniques. In this regard, surface-enhanced Raman spectroscopy (SERS) technique, providing a fingerprint characteristic for each material, would be an interesting approach. The current study encompasses the fabrication of a SERS sensor to study the SARS-CoV-2 S1 (RBD) spike protein of the SARS-CoV-2 virus family. The SERS sensor consists of a silicon nanowires (SiNWs) substrate decorated with plasmonic silver nanoparticles (AgNPs). Both SiNWs fabrication and AgNPs decoration were achieved by a relatively simple wet chemical processing method. The study deliberately projects the factors that influence the growth of silicon nanowires, uniform decoration of AgNPs onto the SiNWs matrix along with detection of Rhodamine-6G (R6G) to optimize the best conditions for enhanced sensing of the spike protein. Increasing the time period of etching process resulted in enhanced SiNWs’ length from 0.55 to 7.34 µm. Furthermore, the variation of the immersion time in the decoration process of AgNPs onto SiNWs ensued the optimum time period for the enhancement in the sensitivity of detection. Tremendous increase in sensitivity of R6G detection was perceived on SiNWs etched for 2 min (length=0.90 µm), followed by 30s of immersion time for their optimal decoration by AgNPs. These SiNWs/AgNPs SERS-based sensors were able to detect the spike protein at a concentration down to 9.3 × 10 −12 M. Strong and dominant peaks at 1280, 1404, 1495, 1541 and 1609 cm −1 were spotted at a fraction of a minute. Moreover, direct, ultra-fast, facile, and affordable optoelectronic SiNWs/AgNPs sensors tuned to function as a biosensor for detecting the spike protein even at a trace level (pico molar concentration). The current findings hold great promise for the utilization of SERS as an innovative approach in the diagnosis domain of infections at very early stages.

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Section: Resultsmentioning

confidence: 99%

Ultra-sensitive and fast optical detection of the spike protein of the SARS-CoV-2 using AgNPs/SiNWs nanohybrid based sensors

Daoudi

Ramachandran

Alawadhi

et al. 2021

Surfaces and Interfaces

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“…This bundle-like structures distribute uniformly on the whole wafers and could be confirmed from the tilt view images. The possible reasons behind this conglomeration may be attributed to Van der Waals attraction between the nanowires [29,30] as well as to the increase in the length of SiNWs that likely causes them to bend to form bouquets under the action of gravity. Otherwise, it was also reported that some nanowires could remain unattached due to inhomogeneous etching induced by a random silver particle distribution [31].…”

Section: Etching Time Effect On Morphology Of Sinw Arraysmentioning

confidence: 99%

Elucidating the Effect of Etching Time Key-Parameter toward Optically and Electrically-Active Silicon Nanowires

et al. 2020

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In this work, vertically aligned silicon nanowires (SiNWs) with relatively high crystallinity have been fabricated through a facile, reliable, and cost-effective metal assisted chemical etching method. After introducing an itemized elucidation of the fabrication process, the effect of varying etching time on morphological, structural, optical, and electrical properties of SiNWs was analysed. The NWs length increased with increasing etching time, whereas the wires filling ratio decreased. The broadband photoluminescence (PL) emission was originated from self-generated silicon nanocrystallites (SiNCs) and their size were derived through an analytical model. FTIR spectroscopy confirms that the PL deterioration for extended time is owing to the restriction of excitation volume and therefore reduction of effective light-emitting crystallites. These SiNWs are very effective in reducing the reflectance to 9-15% in comparison with Si wafer. I-V characteristics revealed that the rectifying behaviour and the diode parameters calculated from conventional thermionic emission and Cheung's model depend on the geometry of SiNWs. We deduce that judicious control of etching time or otherwise SiNWs' length is the key to ensure better optical and electrical properties of SiNWs. Our findings demonstrate that shorter SiNWs are much more optically and electrically active which is auspicious for the use in optoelectronic devices and solar cells applications.Nanomaterials 2020, 10, 404 2 of 18 time-consuming and therefore hindered their applications for commercialized products. In contrast, an effective and promising synthetic method namely metal assisted chemical etching (MACE) has been proposed [2,4,[18][19][20]. This technique is simple, rapid, low cost, and suitable for both industrial and laboratory scales. Moreover, MACE allows to obtain high crystalline SiNWs quality, as well as an easy control of the different parameters including orientation, doping type, length, and diameter.The MACE method basically consists of two procedures, the formation of metal catalysts and the subsequent etching process which can be implemented either in a single step (1-MACE) [10,21] or in two steps (2-MACE) [17-20]. Moreover, the formation method, etching time, etching temperature, metal deposition time, and lastly the etchants' concentrations have a crucial influence on the morphology of SiNWs [2,5,17]. Ghosh et al. reported that SiNWs grown by MACE are usually covered with silicon nanocrystals due to the side wall etching and which are the origin of quantum confinement (QC) effects owing to their small dimensions [20]. Recently, several research groups have succeeded in the synthesis of optically-active SiNWs exhibiting a significant PL emission and a very low reflectance [3,4,17]. On the other hand, Qi et al. have demonstrated the fabrication of electrically-active SiNWs through heavily doped SiNWs with rough surface where a high Schottky barrier exists at the interface of SiNWs and the metal [22]. Nevertheless, further investigation is required t...

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“…The Van der Waals forces between the nanowires and the inhomogeneous etching generated by the random dispersion of silver nanoparticles are two probable explanations for this bundling. [40][41] Cross-sectional SEM image of the SiNW shows the formation of the nanowires with an average height of 14.2 � 0.3 μm that spans the entire surface of the wafer (Figure 2b). The surface of the SiNWs is relatively smooth, with an average wire width of 367 � 27 nm.…”

Section: Resultsmentioning

confidence: 99%

“…The bundle of nanowires is distributed evenly and uniformly throughout the whole wafer surface. The Van der Waals forces between the nanowires and the inhomogeneous etching generated by the random dispersion of silver nanoparticles are two probable explanations for this bundling [40–41] . Cross‐sectional SEM image of the SiNW shows the formation of the nanowires with an average height of 14.2±0.3 μm that spans the entire surface of the wafer (Figure 2b).…”

Section: Resultsmentioning

confidence: 99%

A Free‐Standing Polyaniline/Silicon Nanowire Forest as the Anode for Lithium‐ion Batteries

Eldona

Hawari

Hamid

et al. 2022

Chemistry An Asian Journal

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Despite its high theoretical capacity, silicon anode has limited intrinsic conductivity and experiences significant volume changes during charge-discharge. To overcome these issues, facile metal-assisted chemical etching and in-situ polymerization of aniline are employed to produce a dense 1D polyaniline/silicon nanowire forest without noticeable agglomeration as a free-standing anode for lithium-ion batteries. This hybrid electrode possesses high cycling performance, delivering a stable capacity capped at 2 mAh cm À 2 for 346 cycles of charge-discharge. Maximum capacity of 2 mAh cm À 2 is also achievable at high-rate cell testing of 2 mA cm À 2 , which cannot be obtained by the anode with plain silicon wafer and silicon nanowire only. The introduction of polyaniline on the silicon nanowire is shown to reduce the solid electrolyte interface (SEI) resistance, stabilize the SEI layer, further alleviate the effect of volume changes, and boost the conductivity of the hybrid anode, resulting in the high electrochemical performance of the anode.

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Photocatalytic degradation of cationic and anionic dyes in water using hydrogen-terminated silicon nanowires as catalyst

Cited by 21 publications

References 26 publications

Ultra-sensitive and fast optical detection of the spike protein of the SARS-CoV-2 using AgNPs/SiNWs nanohybrid based sensors

Ultra-sensitive and fast optical detection of the spike protein of the SARS-CoV-2 using AgNPs/SiNWs nanohybrid based sensors

Elucidating the Effect of Etching Time Key-Parameter toward Optically and Electrically-Active Silicon Nanowires

A Free‐Standing Polyaniline/Silicon Nanowire Forest as the Anode for Lithium‐ion Batteries

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